I'm sure I'm missing something simple

Yes... use strict and warnings. You can not construct a variable that way. You should use an array instead of individual scalar variables:

use warnings;
use strict;

my @holdings = qw(
    green
    blue
    yellow
);

for (my $count = 2 ; $count >= 0 ; $count-- ) {
    my $tempvar = $holdings[$count];
    print "$tempvar<br>";
}

print "\n";

__END__

yellow<br>blue<br>green<br>
[download]

See also:

• perlintro
• perldata